The Darkness Inside
by Angel of the Crescent Moon
Summary: Sequel to Inside Me. The darkness will erode the light in Clary and the demon will be released. With only a short amount of time can Jace save the girl he loves. Can Clary be rescued from the shadows or will she never return to the light?
1. Chapter 1

Clary Pov

I'm currently having one of my good hours but I don't know how long it will last. The wall between me and Tenebris is crumbling and the only thing supporting it is me. Unlike before me and Tenebris are now separate, two being's in one mind. The voice in my head is my darker side begging to be in control.

It's been three and a half months since I left Jace, Tenebris has grown stronger. Now I am able to transform into any form and I can heal any wound almost instantly but that depends on my injury. I have broken my promise to Jace, I haven't returned to him. With myself being so unstable at the moment it is hard to control my actions and it would be easy to hurt someone. I also have left my group in England they are currently searching for a cure and write to me twice a week. I am staying with Magnus at his home; he has been helping me with my behaviour. Also covering for me with Jace and keeping them away from the house and more importantly me.

_I will break through, I always find I way in. Just give up now and save yourself all the pain you'll go through._

The voice is like a siren drawing me in, it takes all my strength not to give into the temptation. There are currently three stages of my personality changes. Number one is my usual self; stage two is where I'm torn between the darkness and light. This is when my attitude becomes sarcastic like Jace and I become feisty. However I still consider my moves and how they affect the ones I care about. Lastly phase three is when I am a full on demon but unlike before I don't change into a giant cat whenever I break my nail. I stay in my natural form but I'm devious, malicious and damn right evil. Magnus has put an enchantment on me so he can tell which stage I'm in. I have a nasty habit of tricking him. Stage 1 my nails are a neutral colour, stage 2 red and stage 3 black.

Right now I'm sat in Magnus living room being sick in a bucket. Not that pleasant I know but as Tenebris grows stronger, I grow weaker and the more it fights the more ill I become.

_It will only get worse, give up._

The voice begs in my head. Magnus stole's into the room, his sparkly jacket blinding me. He hands me a handkerchief. I wipe my mouth and while the sickness feeling has settled I attempt to speak. "How is he?" I ask. Magnus went to the Institute today; he and Alec had a lunch date. Magnus gives me a sympathetic look as he sits next to me.

"Jace is getting more anxious and worried. This isn't healthy for him; he needs something from you Clary."

"Magnus, you know-"I was stopped mid sentence as I vomited in the bucket. Magnus takes advantage and speaks.

"You haven't seen him Clary, he is a wreck." Guilt, sympathy, hurt fills me. The emotions overwhelm me and leave me venerable.

_Goodbye Clary._

I looked down at my nails and examine them, I love the colour red. I put the bucket and stand up. I look at my body; I'm wearing pyjamas which are way too big. God what on earth am I wearing? I announce to Magnus that I'm going to get changed. I like Magnus he makes good company, he lets me wander around his house but he puts spells so I can't leave. I search through the wardrobe, do I own anything sexy. After digging through a pile of clothes that belongs in a charity shop, I find a Black, one sleeved tight fitting dress that goes to my mid thigh. As I admire my red eyes, I hear banging on the door. That's when I catch the scent, pretty boys here. I stand in the shadows of the living room out of sight as goldilocks enters with Magnus.

Golden boy is hot; my heart flutters when I look at him. I feel warmth and excitement spread through my body just by looking at him. Love is a deadly cage which it seems I am trapped in.

"Magnus, please use a tracking spell or something just find Clary?" How sweet, he's smiting too. Magnus makes up some excuses, obviously trying to get him out of the house. It's time to cause some mayhem! I step into the light. Jace freezes and stares at me.

"Clary?" He gasps; you would think he had seen a ghost. I put on a flirty smile and wave at him. Magnus groans.

"Clary sit down and stay quiet."He commands. I salute him and say

"Whatever you say, Captain." I sit on the couch and watch the show while playing with my hair. Jace is full of anger.

"She was here the entire time and you didn't tell me." This was going to be better than I thought. Magnus walked closer.

"Look Jace, you need to understand that Clary is different now. The darkness has been expanding quicker than we assumed and she has been corrupted."

_Let me take full control, it'll be more fun. _Not yet, I still wasn't done causing trouble.

I thought it was time to intervene and help Magnus. I look at Jace

"Don't be mad at Magnus, it's what I wanted." Jace was focusing only on me now.

"What? Clary I thought you were in danger or in trouble."I saw the hurt in his eyes. He is so whipped. I needed to sort this out, our feelings couldn't continue. I needed to fall out of love with him.

"Sorry golden boy, I like you but love is impractical and let's face it stupid."Goldilocks looked like I had spat in his face. I felt a wave of happiness and also a built of guilt but it was easily forgotten.

Time for the show's finale. _Finally I'm in full control._

_Magnus gazed at my black nails and mumble "Perfect timing."_


	2. Tenebris

**Hey guys! Here's a new chapter for you, please enjoy. Give me your feedback on what you love and what you don't, thank you!**

Clary (Stage 3) Pov:

Before Magnus can convince Jace to leave, I walk up to him and kiss him slowly and delicately. Then I pull away and whisper.

"I missed you so much." He smiled and silently said "Clary." He sound so relieved. It's going to be easier to mess with him than I thought. Jace kissed me again, it was full of passion. Magnus placed his hand on my shoulder, time to start the chaos. I let out a blood curdling scream and push Magnus off me. Then run behind Jace and whimpered.

"Keep him away from me please." Jace turned around and faced me his hands cupped my face. He quickly glanced at Magnus and then said.

"Clary, there's nothing to be afraid off. Magnus won't hurt you, please tell me what's wrong?" I began whimpering again and look deep into his eyes. I should have a best actress award.

"The pain! I can't go through that again Jace, please don't make me. Please."I beg him. I could see the confusion in his eyes. He held me close to him and rested his chin on my head.

"Please tell me what happened?" He cooed. By the angel, was it always this easy to mess with someone? Just before I had a chance to explain, Magnus spoke up. He sounded annoyed but who could blame him?

"I've had enough of this!" He announces and then everything goes dark.

Jace pov:

Clary went limp in my arms. What is going on? I look at Magnus.

"What by the angel is going on?" anger laced in my voice. He doesn't answer me but just signals for me to follow him. I pick Clary up bridal style and go after him.

I go into an empty room with white walls and carpets. There is a pentagon of crystals in centre of the room, what by the angel has Magnus been up to. Magnus stood next to the crystal and said.

"Place Clary down in the pentagram." I did as he had asked and reluctantly stepped out of the crystal boundary. Before Magnus could leave or divert the conversation, I ask.

"Will you explain to me what by the angel is going on here?" He put his hand up signalling for me to be silent. I was about to resist but then he summoned a book in his hand and began mumbling words however he spoke to quietly so I couldn't recognise the language but it sounded like they're old English or Latin. A purple, glistening force field rise from the crystal and that's when Magnus decides to speak.

"Jace I'm going to explain but please do not interrupt me. You have to understand that Clary is not the same as she was three months ago. During Clary's absence, the demon side of her, Tenebris as she prefers to call it has grown much stronger. As Tenebris strengthens, the Clary we all know and love weakens and she is starting to get ill. Sebastian and the others are searching for a cure still while Clary stays here with me. I've been attempting to slow the process of the eroding but it isn't going so well.

I need to warn you that Clary has now three different personalities. The first one is the normal Clary, number two is when she is in between the light and the darkness and three is when she is an evil and just a glimpse of the girl you once knew. When I knocked her out, she was at stage three. Luckily my magic is still useful for something and I have created a way so we know what phase she is in. Being the stylish warlock I am, I've done a trick so her nails change colour depending on her phase. One equals natural, two is red and three means black." I was processing what I just found out and then Clary began to stir.

Clary's (Stage 3) pov:

I woke up on the ground; I saw the purple shimmer surrounded me.

"Not this again, Magnus." I cooed. I stood up again and looked at the warlock expectantly. A chair appeared behind me and I sat down. I crossed my legs, my gaze fell to Jace he hadn't moved or even spoke since I awoken.

"Can me and goldilocks have a moment together." I ask my gaze still on Jace. I heard shuffling and guessed Magnus had left.

"So why didn't you protect me?"I questioned. Jace finally spoke. "You were never in danger. You know Magnus wouldn't hurt you." I chuckled and made my voice sound sad. "Why didn't you protect me from my brother? Why did you let him turn me into this thing?" Jace looked at me for the first time since I had awakened.

"I tried." He whispered. The delicious pain in his eyes and voice.

"Because of you, I spent months trapped with my brother being his little guinea pig. Because of you, my own mother wants me dead. How does it feel to know that you destroyed my life? That you are the reason I'm like this." I continued to rant on until Jace shouts "Shut up!" Now it's getting fun.

"Shut up or what? Will you kill Jace? I'll do it for you." I smile and licked my lips. I pulled my dagger which was hidden in my dress and stabbed myself in the stomach. His eyes almost popped out of his skull. I would heal in a few minutes, my blood stained my dagger.

Then the world went dark.


	3. Author Note!

**Sorry guys but I haven't been getting much feedback on the story so I'm going to take a break and refresh my TMI writing idea's. I will return to this story but the good news is that I am writing a Loki x oc fanfiction called Cold Trickery which I hope you will check out thanks for all your support.**


	4. I love you Clarissa

**Hey guys! Here is the next chapter and I am sorry for taking this long to post it. **

***Disclaimer* I do not own any of the characters which feature in the Mortal Instrument series they belong to the amazing Cassandra Clare.**

Clary's (Stage 1) Pov.

I opened my eyes to see Jace whispering something to Magnus. Wait, Jace? Then the memories of the past hours are flooding. What have done?

"Jace." I whisper, trying to get his attention. His golden eyes meet mine and I melt inside. I see his eyes quickly go to my nails and then return to my eyes. He ran inside my cage and hugs me. His grip is too tight and a wave of nausea hits me. I push him away and it pains me to see the pain in his eyes. I can't speak because if I speak I will be sick so instead I shot my hand in the air to signal for Magnus to poof me a bucket. Immediately a red bucket appears in my hands, luckily Magnus has perfect timing. Jace held my hair and rubbed my back attempting to comfort me. I hate him to see me like this.

When I feel reasonably okay, I speak slowly. "You shouldn't be here Jace."

"It's been three months Clary and Jace Wayland never breaks his promises." A small smile crept onto my face.

"As you can see, I am a bit under the weather at the moment." I say trying to lighten up the moment.

Then he kisses me slowly, gently and passionately. My skin tingles as if it is on fire.

"I love you Clarissa! I love you more than I drowning man love the air. I adore you than poor man treasures money. I worship you more than warlock worships his spell book. My heart breaks a little every time I see you in pain but my heart would be shattered if something happened to you and I wasn't here by your side. I will stay by you, fight for you and protect you from all the dangers in this world and if we die and there is life after this then I will hunt every demon and search the new world until I am with you again."

I step away from him and gaze into his eyes.

"I've never been good with words but I want to tell-" Jace interrupted me.

"Clary you don't have to-" I interrupted him.

"Like I said I've never been very good with words so I am just going to explain how I feel. When I'm close to you-" I closed the gap between us.

"My skin feels likes it's on fire. When I touch you-" I wrap my arms around his neck.

"Electricity shoots through my body and when I kiss you-" My lips are only millimetres away from his.

"I melt." Then Jace kisses me but instead of being gentle and slow this is fast, impatient and rough. I can't get enough of him. Then that's when I smelt it, the blood of the Nephlim, there must be over twenty of them. It's time! I break away from him. Then I stroke his face, he stares at my black nails but before he can say anything I put my finger on his lips.

"Come and play with me Jace."I whisper. He nods his head and I silently apologise before throwing him on the floor and transforming into the full demon. I position myself so I'm over his body, my teeth grazing his neck and my tails surround his head. Then the clave broke in the door and the leader shouts "Release the boy and return to your natural state. Clarissa Adele Morgenstein you are now a prisoner of the clave." I did what they asked.

*****BREAK*****BREAK*****BREAK*****BREAK*****BREAK*****BREAK*****BREAK****BREAK

I was bloody, aching and beaten it's a good thing I healed fast. I had only been in the interrogation room for eighteen minutes I was already chained to the wall with a burning poker in my stomach. The man with brown hair and brown eyes asked again for the twelfth time.

"Why were you at Magnus Bane's house?"

_Flashback:_

_It's been just under three months since I left Jace and my family and I'm putting them in danger by being here but I need help so that's why I've came to Magnus. When I walked in the room Magnus house, he was going through his wardrobe probably to find something to wear today._

"_Magnus." I said. Magnus turned around and embraced me into one of his bear hugs. _

"_Clary, I'm so happy to see you." I put on a small smile but of course Magnus saw through it and raised his eyebrow._

"_I need help! I need you to make Jace think that Valentine was right about the demon blood erasing the light in me. I need you to help me make Jace believe I'm evil!"_

**Sorry about the cliffhanger but I couldn't resist adding it, please review.**


	5. Flashback

**Hi everyone! Thanks for reading and I'm proud to announce the The Darkness Inside is back on track and hopefully I will update again soon.**

I_ was sat on Magnus's chair with a hot chocolate that had just appeared in my hands. Magnus was opposite me waiting for an explanation but I was thinking carefully on how to word it without him going nuts._

_"I need a spell." I say each word said slowly. He seemed relieved at my request._

_"Why are you asking all mysterious and Sebastian-like if you just needed a spell." Now the more complicated spell._

_"I need you to perform a spell on Alec, Izzy, Simon and Jace." I saw him stiffen up immediately._

_"What kind of spell." He said each word as if it was a bomb which can explode at anytime._

_"I want you to wipe their memories of me." His cat eyes almost popped out of his head._

_"Why on earth would you want to do that Clary?" His voice and eyes flared with anger._

_"There is an uprising in the demon realms. A demon Alzeric is hunting down greater demons fighting and killing to get at the top of the hierarchy. Me and the others have been searching for him but he is practically impossible to destroy and just last week he attack Samuel. As he grows stronger, the more powerful demons he is hunting. Sooner or later he is going to come after me and while Jace, Isabelle, Alec and Simon are close to me they are at risk." I finish out of breath from my rambling._

_His eyes soften and he says delicately. "Clary, this is not the way to do things. Do you remember how much it hurt when you realised what your mother hired me to do? Imagine how much it will hurt them if they ever found out?" I returned his soft gaze._

_"I know if they ever found out then they would be mad but I can take them hating me but it would break both of us if they died because we didn't try to do this. If you knew you had a chance to save to Alec wouldn't you do it despite the consequences it had on you?" He moved his hand through his hair while he contemplated what to do._

_"The spell will be easier to do if the bond between you is weakened especially with Jace." I can't believe he is agreeing. I had thought through this over a thousand times in my head. Every inch I went through, every single detail I had tried to consider._

_"They don't know Valentine was just trying to scare us by say my goodness was going to be eroded. So we will let them believe he was telling the truth, that I am an evil, cold-hearted demon." He nodded and the plan began._

_*Flashblack over*_

I was brought out of the flashback by the burning in my rib cage. I glared at the questioner.

"Do I have to ask you again, Clarissa?"

"I wanted a spell to track a demon for me." I lied. He smiled triumphantly as he removed the red stained weapon.

"Why?" He continued to interrogate.

I laughed lightly as my blood red eyes bore into his brown eyes. "I want to kill it, silly." I make my voice sweet, innocent and almost child-like. Now that wasn't a lie. He put the blade back into the fire.

"Why do you want to this demon dead?" I guess I should tell them. They need to be ready or they wouldn't have a chance.

"You know the usual thing. Big, bad demon wants to get to the top of the hierarchy and he stupidly picked a fight with an ally of mine so I want to teach him a lesson." He gave a worried glance to his partner and the other nephlim left. The one who was stayed continued to speak.

"Just to confirm your statement, by teaching him a lesson you mean kill him?"I smiled showing my bloody teeth. By the angel I'm crazy.

"Torturing actually, you seem pretty good at it maybe I could get some tips." Then I felt metal hit the side of my head and once again I was consumed by darkness.

2 Months Later...

Aczella **(Name of the greater demon)** had grown stronger and was killing much more than he did before; well that's what I gathered from the guards outside my cell. Two months I have been trapped in this freezing cell when I could have been out there and killed that demon by now. Aczella has begun to make his moves bolder and he is now killing shadow hunters. Everyone has started to worry and soon the shadow hunters will be forced to take action. Honestly I am surprised they've left it this long.

There are voices outside my door more than usual I attempted to move forward so I can hear better however the chains connecting me to a metallic wall seems to have plans. Then a man entered my cell, four tall body guards followed him and stood beside him was the one and only cat eye high warlock. Did they really need this much back up? I'm hurt that they don't trust me!

"We are willing to make a deal with you tenebris." The one in the centre announced. I rattle the chains.

"If we are going to talk I would be prefer to at least move." Magnus fingers sparked and the chains vanished. The leader sent Magnus a questioning look but he just shrugged. I rubbed my sore wrists as the middle man started talking again.

"We need your help to keep Aczella before he is able to kill anymore of our men." I was about to deny them to test how desperate they wee but I decided against it when I received a warning look from Magnus.

"Sure, I'm in a knight in shining armour mood." I begin to stand in spite of the screams coming from my legs.

"So what's the plan then?" I ask as I walk towards the group of men in black leather jackets and combat boots.

"You will do everything we say. You will work with a team of shadowhunters, they're considered to be the best in the world." He can't mean Jace but Magnus confirmed my worries by a single nod.

I was being guided to some hall by two shadow hunter body guards from early and Magnus obviously came to. Did he wipe their memories? I change my appearance just in case the sparkly warlock did his part of the deal. If they see the real me, it may be too much and could trigger a memory. I now have dark brown hair layered hair, electric blue fringe and hazel eyes.

The hall was large and grand like every other room here, well apart from the dungeons they've got more of a retro theme. Then my heart stopped, Jace was staring at me with the same cold golden eyes that I met in the pandemonium.

Then the other two body guards left saying we needed time to come to terms with one another. Alec was stood next to Magnus looking at me like I could freeze them with my eyes, Isabelle looked at me with complete hatred and well for Jace he stared at me coldly, superiorly whilst playing with a dagger.

"I expected more from the great and mighty tenebris." Jace said disappointed. I chuckled lightly but he didn't notice. He threw a dagger at me and I easily caught it. "Hallelujah, the demon has basic reflexes."

"I'm not here to spar now why don't you tell me what you already know about Aczella." I forced my voice cold and hard.

"That he is a maniac almost as bad as your brother." I growled and Alec stepped forth along with Iz.

"Be careful of how you speak of my brother" I warned. Jace just laugh. Every word, every insult was like a stab to the gut.

"Why don't you go back to combing your hair because you obviously aren't the demon we are looking for?" I flashed my red eyes, extended my claws and flashed my canines.

"Why don't you take out your sword and find out?" I threatened. We both stepped forward ready to fight but obviously I wouldn't hurt him, I'm just following my instinct.

"Enough!" Magnus shouted. I returned back to the regular mundane disguise.

"Retreat like the scared princess you are." I said provoking him. I don't know why I am doing this, it just feels natural like I can't stop what happens between my brain and my mouth.

Then again the room is filled with Jace sarcastic laugh.

"I'm not afraid of anything." As he walked back to Alec's side, I quietly taunted.

"Quack."

**Just a general summary of what Magnus and Clary did.**

**Aczella is a new threat which is hunting down all of the greater demons. Clary is one the target list and needs to protect those she loves so they wont be used against her. She convinces Magnus to help her wipe Jaces and the gangs memory of her however the spell will be more difficult to achieve aslong as their still is a strong bond between her and Jace. So Clary turns into an actress and pretends that her light is eroding (Valentine lied about that) and she pretended to be going evil by pretending her personality was spilt. Once the bond was slightly weakened, Magnus would contact the clave and inform them of Clary's were abouts. When the clave arrived, Clary pretended to attack Jace so they wouldn't expect him of any treason. Once Clary was gone, Magnus enchanted four bracelets and gave them to each member. Once these accesories were on the weilder would forget everything about Clary. **

**That is basically it.**

**So what or who do you think this new mystery demon Aczella should be?**

**Do you want more bickering between Jace and Clary?**

**Do you want Simon to show up soon? **

**Please reveiw and give me your feedback! Until the next chapter...The Parasite and The Monster.**


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